<?php
/**
 * 确定是不是一个有效的url
 * @param string $url
 * @return bool
 * @version $Id: is_url.func.php 4641 2011-11-29 13:51:09Z yaoying $
 */
function is_url($url)
{
	$re = preg_match('/^(http:\/\/|https:\/\/)[a-zA-Z0-9.]+(\/)?[-a-zA-Z0-9@:%_\\+.~#?$()&\/\=]*$/', $url);
	return (bool)$re;
}
